The present disclosure herein relates to a display device and a method for manufacturing the same.
Flat display devices may be largely classified into two main groups such as a light emitting type and a light receiving type. Examples of the light emitting type are a flat cathode ray tube, a plasma display panel, an electroluminescent device and the like. An example of the light receiving type is a liquid crystal display. Among these, the electroluminescent device has advantages in that a viewing angle is wide, contrast is excellent, and a response speed is fast, and thus, has been receiving attention as a next generation display device. Such electro luminescent devices are classified into a non-organic electroluminescent device and an organic electroluminescent device according to a material that forms a light emitting layer.
Among these, the organic electroluminescent device is a self-emitting type of display that electrically excites a fluorescent organic compound to emit light, and since the organic electroluminescent device is operable at a low voltage and may be easily slimmed, the organic electroluminescent device receives attention as a next generation display having a wider viewing angle, a faster response speed and the like, in comparison to liquid crystal display.
The organic electroluminescent device has a light emitting layer including an organic material between an anode electrode and a cathode electrode. In the organic electroluminescent device, when anode and cathode voltages are applied on the electrodes, respectively, holes are moved from the anode electrode to the light emitting layer via a hole transfer layer, and electrons are moved from the cathode electrode to the light emitting layer via an electron transfer layer, and then the electrons and holes are recombined with each other in the light emitting layer to generate excitons. When the excitons are changed from an excited state to a ground state, fluorescent molecules in the light emitting layer emit light to form an image.